As we know, the natural sunlight is an indispensable source of life for the living organisms; for the man,
however, it plays various roles with remarkable psychological effects not exclusively bound to the quality of the vision of individuals, but for their well-being as well: the feeling of a well aired place, the perception of the true natural colours, the regulation of the biological cycles. The abstention from its benefits for long periods is the principal cause of some depressing pathologies. continue reading